DORCHESTER DR-LA 30, DR-LA 40, DR-LA 60, DR-LA 75, DR-LA 95 User Manual

...

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Dorchester DR-LA Range

of Hot Water Storage Heaters

Open Flue, Direct Gas Fired Hot Water Storage Heaters

with Automatic Ignition

for Domestic Hot Water Installations

Installation, Commissioning

and Servicing Instructions

DORCHESTER DR-LA 30, 40, 45, 60, 75, 95, 110 Models

NATURAL GAS I2H LPG I3+

NOTE: THESE INSTRUCTIONS MUST BE READ AND UNDERSTOOD BEFORE INSTALLING, COMMISSIONING, OPERATING OR SERVICING EQUIPMENT.

THIS WATER HEATER IS FOR USE ON GROUP H NATURAL GAS (2 LPG (3 DOCUMENT IS FOUND RELATING TO SPECIFIC GAS TO BE FIRED BEFORE FIRING HEATER.

THIS WATER HEATER COMPLIES WITH ALL RELEVANT EUROPEAN DIRECTIVES.

PUBLICATION NO. 500001137 ISSUE ‘A’ SEPTEMBER 2005

FAMILY) I3+. PLEASE ENSURE RELEVANT INFORMATION REQUIRED WITHIN

FAMILY) I2H OR

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1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - 7

1.1 About the water heater - - - - - - - - - - - - - - - - - - - - - - - - - - - 7

1.2 What to do if you smell gas- - - - - - - - - - - - - - - - - - - - - - - - - 7

1.3 Regulations and documents - - - - - - - - - - - - - - - - - - - - - - - - 7

1.4 Target groups - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 8

1.5 Maintenance - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9

1.6 Forms of notation - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 9

1.7 Overview of this document - - - - - - - - - - - - - - - - - - - - - - - - 10

2 Functioning of the water heater - - - - - - - - - - - - - - - - 11

2.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 11

2.2 Functional description of the water heater - - - - - - - - - - - - - - - - 12

2.3 The water heater’s heating cycle - - - - - - - - - - - - - - - - - - - - - 13

2.4 Protection for the water heater - - - - - - - - - - - - - - - - - - - - - - 13

2.4.1 Water temperature protection - - - - - - - - - - - - - - - - - 13

2.4.2 Combustion products discharge safety device - - - - - - - - - 14

2.4.3 flame probe - - - - - - - - - - - - - - - - - - - - - - - - - - 14

2.5 Safety of the installation - - - - - - - - - - - - - - - - - - - - - - - - - 14

2.5.1 Unvented installation - - - - - - - - - - - - - - - - - - - - - 14

2.5.2 Vented installation- - - - - - - - - - - - - - - - - - - - - - - 14

2.5.3 Temparature and Pressure valve (T&P valve) - - - - - - - - - 14

2.6 Indicators and Alarms - - - - - - - - - - - - - - - - - - - - - - - - - - 14

2.6.1 Volt Free Contacts - - - - - - - - - - - - - - - - - - - - - - 14

2.7 Options - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 15

2.7.1 LPG- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 15

2.7.2 Unvented Supply - - - - - - - - - - - - - - - - - - - - - - - 15

2.7.3 Top to Bottom Circulation - - - - - - - - - - - - - - - - - - - 15

3 Installation - - - - - - - - - - - - - - - - - - - - - - - - - - - 17

3.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 17

3.2 Packaging - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 17

3.3 Environmental conditions- - - - - - - - - - - - - - - - - - - - - - - - - 17

3.3.1 Humidity and ambient temperature- - - - - - - - - - - - - - - 18

3.3.2 Maximum floor loading - - - - - - - - - - - - - - - - - - - - 18

3.3.3 Working clearances - - - - - - - - - - - - - - - - - - - - - - 18

3.4 Technical specifications - - - - - - - - - - - - - - - - - - - - - - - - - 20

3.5 Installation diagram - - - - - - - - - - - - - - - - - - - - - - - - - - - 24

3.6 Water connections, Unvented - - - - - - - - - - - - - - - - - - - - - - 25

3.6.1 Cold water side - - - - - - - - - - - - - - - - - - - - - - - - 25

3.6.2 Top to bottom recirculating pump - - - - - - - - - - - - - - - 25

3.6.3 Hot water side- - - - - - - - - - - - - - - - - - - - - - - - - 25

3.6.4 Drain valve - - - - - - - - - - - - - - - - - - - - - - - - - - 25

3.6.5 Circulation pipe - - - - - - - - - - - - - - - - - - - - - - - - 25

3.7 Water connections, Vented- - - - - - - - - - - - - - - - - - - - - - - - 26

3.7.1 Cold water side - - - - - - - - - - - - - - - - - - - - - - - - 26

3.7.2 Top to bottom recirculating pump - - - - - - - - - - - - - - - 26

3.7.3 Hot water side- - - - - - - - - - - - - - - - - - - - - - - - - 26

3.7.4 Circulation pipe - - - - - - - - - - - - - - - - - - - - - - - - 26

3.8 Gas connection - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 26

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3.9 Flue gas discharge - - - - - - - - - - - - - - - - - - - - - - - - - - - - 27

3.9.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - 27

3.9.2 Fitting the draught diverter - - - - - - - - - - - - - - - - - - - 27

3.9.3 Flue gas thermostat assembly - - - - - - - - - - - - - - - - - 28

3.10 Electrical connection - - - - - - - - - - - - - - - - - - - - - - - - - - - 29

3.10.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - 29

3.10.2 Preparation- - - - - - - - - - - - - - - - - - - - - - - - - - - 29

3.10.3 Mains power - - - - - - - - - - - - - - - - - - - - - - - - - - 30

3.11 Checking the supply pressure and burner pressure - - - - - - - - - - - - 31

3.12 Conversion to a different gas category - - - - - - - - - - - - - - - - - - - 33

3.12.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - 33

3.12.2 Conversion to a different gas category DR-LA 30 through 95 - - 34

3.12.3 Conversion to a different gas category, DR-LA110 - - - - - - - 36

4 Filling and draining - - - - - - - - - - - - - - - - - - - - - - - 39

4.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 39

4.2 Filling the water heater - - - - - - - - - - - - - - - - - - - - - - - - - - 40

4.2.1 Filling unvented installations - - - - - - - - - - - - - - - - - - 40

4.2.2 Filling vented installations- - - - - - - - - - - - - - - - - - - - 40

4.3 Draining the water heater - - - - - - - - - - - - - - - - - - - - - - - - - 40

4.3.1 Draining unvented installations - - - - - - - - - - - - - - - - - 40

4.3.2 Draining vented installations - - - - - - - - - - - - - - - - - - 41

5 Controls- - - - - - - - - - - - - - - - - - - - - - - - - - - - - 43

5.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 43

5.2 Control panel - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 43

5.3 Explanation of the symbols - - - - - - - - - - - - - - - - - - - - - - - - 44

5.4 ON/OFF switch - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 44

5.5 Control thermostat - - - - - - - - - - - - - - - - - - - - - - - - - - - - 44

5.6 Burner control reset button - - - - - - - - - - - - - - - - - - - - - - - - 44

5.7 Flue gas thermostat reset button - - - - - - - - - - - - - - - - - - - - - 44

6 Status of the water heater - - - - - - - - - - - - - - - - - - - 47

6.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 47

6.2 Operating states - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 47

6.3 Error states - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 47

7 Starting up and shutting down - - - - - - - - - - - - - - - - - 49

7.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 49

7.2 Starting up - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 49

7.3 Shutting down- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 49

7.3.1 Shut the water heater down for brief periods ("OFF mode") - - - 49

7.3.2 Isolate the water heater from the power supply - - - - - - - - - 49

7.3.3 Shut the water heater down for a longer period - - - - - - - - - 49

7.4 Heating cycle - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 50

8 Troubleshooting - - - - - - - - - - - - - - - - - - - - - - - - 51

8.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 51

8.2 Troubleshooting table for general errors - - - - - - - - - - - - - - - - - - 52

8.3 Troubleshooting table "no hot water"- - - - - - - - - - - - - - - - - - - - 53

8.4 Troubleshooting table "insufficient hot water’" - - - - - - - - - - - - - - - 55

9 Maintenance - - - - - - - - - - - - - - - - - - - - - - - - - - 57

9.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 57

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9.2 Preparing for maintenance - - - - - - - - - - - - - - - - - - - - - - - - 57

9.3 Water-side maintenance - - - - - - - - - - - - - - - - - - - - - - - - - 58

9.3.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - 58

9.3.2 Checking the anodes - - - - - - - - - - - - - - - - - - - - - 58

9.3.3 Descaling and cleaning the heater - - - - - - - - - - - - - - - 58

9.4 Gas-side maintenance - - - - - - - - - - - - - - - - - - - - - - - - - - 59

9.4.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - 59

9.4.2 Cleaning the burners - - - - - - - - - - - - - - - - - - - - - 59

9.4.3 Cleaning the orifices - - - - - - - - - - - - - - - - - - - - - - 60

9.4.4 Checking the flue baffles - - - - - - - - - - - - - - - - - - - 60

9.5 Finalising maintenance- - - - - - - - - - - - - - - - - - - - - - - - - - 60

A Appendices - - - - - - - - - - - - - - - - - - - - - - - - - - - 61

1.1 Introduction - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 61

1.2 Electrical diagram DR-LA - - - - - - - - - - - - - - - - - - - - - - - - 62

1.2.1 Electrical diagram DR-LA 30 through 95 and 110 (natural gas) - 62

1.2.2 Electrical diagram DR-LA 110 (LP gas) - - - - - - - - - - - - 63

Instruction manual DR-LA 5

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6 Instruction manual DR-LA

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1 Introduction

About the water heater

1.1 About the water heater

0063

1.2 What to do if you smell gas

This manual describes how to install, service and use an DR-LA-water heater. An DR-LA water heater is a gas-fired open water heater without a fan. DR-LA water heaters are fitted with a combustion products discharge safety device. The DR-LA belongs to water heater category B manual is applicable to types: DR-LA 30, DR-LA 40, DR-LA 45, DR-LA 60, DRLA 75, DR-LA 95 and DR-LA 110.

The manner of construction and features of the water heater are in conformance with the European standard for gas-fired storage water heaters for the production of domestic hot water (EN 89). The water heaters are therefore compliant with the European Directive for Gas Appliances and have the right to bear the CE mark.

Warning

Read this manual carefully before starting up the water heater. Failure to read the manual and to follow the printed instructions may lead to personal injury and damage to the water heater.

Warning

Whenever there is a smell of gas:

No naked flames! No smoking!

Avoid causing sparks! Do not use any electrical equipment or switch, i.e. no telephones, plugs or bells!

. The information in this

11B S

1.3 Regulations and documents

Shut off the mains gas supply!

Open windows and doors!

Warn occupants and leave the building!

After leaving the building, alert the gas distribution company or installation engineer.

Gas Safety Installations and Use Regulations 1998, (As amended). It is law that all gas appliances are installed by competent persons, in accordance with the above regulations. Failure to install appliances correctly could lead to prosecution. It is in your own interest, and that of safety, to ensure that this law is complied with.

The installation of the boiler MUST be in accordance with the relevant requirements of the Gas Safety Regulations, Building Regulations, IEE Regulations and the Water Supply (water fittings) Regulations.

The installation should also be in accordance with any relevant requirements of the HSE, local gas region and local authority and the relevant recommendations of the following documents:

Instruction manual DR-LA 7

Introduction

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British Standards

• BS 6891: Specification for installation of low pressure gas pipework of up to 28 mm (R1) in domestic premises (2nd family gas). For larger installations see IGE/UP/2 below.

• BS 6798: Specification for installation of gas-fired boilers of rated input not exceeding 70 kW net.

• BS 6644: Specification for installation of gas-fired hot water boilers of rated inputs between 60 kW and 2 MW (2nd and 3rd family gases).

• BS 6700: Specification for design, installation, testing and maintenance of services supplying water for domestic use within buildings and their curtilages.

• BS EN 806-2: Specification for installations inside buildings conveying water for human consumption. Part 2: Design.

• BS 5546: Specification for installation of hot water supplies for domestic purposes, using gas-fired appliances of rated input not exceeding 70 kW.

• BS 5440: Installation and maintenance of flues and ventilation for gas appliances of rated input not exceeding 70 kW net (1st, 2nd and 3rd family gases). Part 1: Flues. Part 2: Ventilation.

Institute of Gas Engineers and Managers Publications

• IGE/UP/1 Soundness testing and purging of industrial and commercial gas installations.

• IGE/UP/1A Soundness testing and direct purging of small low pressure industrial and commercial natural gas installations.

• IGE/UP/2 Gas installation pipework, boosters and compressors on industrial and commercial premises.

• IGE/UP/10 Installation of gas appliances in industrial and commercial premises. Part 1: flued appliances.

CIBSE Publications:- "CIBSE Guide"

Section B4 : Water Service Systems.

1.4 Target groups The three target groups for this manual are:

• (end) users;

• installation engineers;

• service and maintenance engineers.

Symbols on each page indicate the target groups for whom the information is intended. See Table 1.1.

Table 1. 1 Target group symbols

Symbol Target group

(End) user

installation engineer

Service and maintenance engineer

8 Instruction manual DR-LA

Maintenance

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1.5 Maintenance A service should be carried out at least once a year, both on the water side and

on the gas side. Maintenance frequency depends, among other things, on the water quality, the average burning time per day and the set water temperature.

n Caution

To determine the correct maintenance frequency, it is recommended to arrange for the service and maintenance engineer to check the water heater on both the water and gas side, three months after installation. Based on this check, the best maintenance frequency can be determined.

n Caution

Regular maintenance extends the service life of the water heater.

Both the end user and the service and maintenance engineer are responsible for regular maintenance. They will need to establish clear agreements on this.

n Caution

If the water heater is not regularly maintained, the warranty will become void.

1.6 Forms of notation The following notation is used in this manual:

n Caution

Important information

cNote

Ignoring this information can lead to the water heater being damaged.

Warning

Failure to carefully read this information may lead to danger of personal injury and serious damage to the water heater.

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Introduction

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1.7 Overview of this document

Table 1. 2 Contents of document

Chapter Target groups Description

2 Functioning of the water heater

3Installation

4 Filling and draining

Table 1.2 provides an overview of the contents of this document.

This chapter describes how the water heater functions.

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This chapter describes the installation activity to be completed

before you actually start up the water heater.

This chapter describes how to fill and drain the water heater.

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5 Controls

6 Status of the water heater

7 Starting up and shutting down

8 Troubleshooting

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This chapter describes the water heater’s control panel and how to use it.

This chapter describes each status (state) that the water heater may be in and how to respond, if necessary.

This chapter describes how to start up the water heater and how to shut it down for a brief or long period of time. The general heating cycle of the water heater is also described.

This chapter is mainly intended for the installation engineer and the service and maintenance engineer. It describes water heater errors. These errors are indicated on the display. A table of possible causes and solutions is provided. End users may also refer to this chapter for additional information about the water heater.

9 Maintenance

This chapter sets out the maintenance tasks to be carried out during a service.

10 Instruction manual DR-LA

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2 Functioning of the

water heater

2.1 Introduction Topics covered in this chapter:

• Functional description of the water heater;

• The water heater’s heating cycle;

• Protection for the water heater;

• Safety of the installation.

Introduction

Instruction manual DR-LA 11

Functioning of the water heater

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2.2 Functional description of the water heater

Legend

a flue gas discharge

b draught diverter

c anodes

d flue tubes

e flue baffles

f flue gas thermostat

g flue gas thermostat sensor

h insulation layer

i hot water tank

j cleaning opening

k drain valve

l combustion chamber

m radiation shield/condensation

tray

n gas control

o safety thermostat sensor

p high-limit thermostat sensor

q burner control

r hot water outlet

s control panel

t control thermostat

u high-limit thermostat

v safety thermostat

w frost thermostat

x control thermostat sensor

y frost thermostat sensor

z hot surface igniter

A flame probe

B cold water inlet

C bar burners/burner tray

Figure 2.1 shows a cut-away view of the water heater.

d e

f g

Figure 2.1 Cut-away view of the water heater

o p

s t u

x y

IMD-0133

In this water heater the cold water enters the bottom of the it via the cold water inlet B. The heat of combustion is transferred to the water through the combustion chamber l and flue tubes d. The heated tap water leaves the heater through the hot water outlet r. Once the water heater is completely filled with water, it remains constantly under water supply pressure. As hot water from the water heater is consumed, it is continuously replenished with cold water.

The gas required for combustion flows into the manifold via the gas control n. Orifices are located within the manifold. Via these orifices, the gas enters the bar burners C. Together, the bar burners constitute the burner tray. As the gas is injected into the bar burners, the primary air required for combustion is also drawn in

1. The narrow opening in the orifices accelerates the gas flow. This causes a partial vacuum. The

(1)

. Additional air is drawn through the openings in the burner tray. The

effect of this partial vacuum is to draw the air into the flow (the Venturi effect).

12 Instruction manual DR-LA

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The water heater’s heating cycle

hot surface igniter z ensures the ignition of the gas/air mixture. The flue gases generated by this combustion are led through the flue tubes d. There are flue baffles e located in the flue tubes. These slow down the flue gas exhaust, improving the heat transfer efficiency. The flue gases leave the water heater via the draught diverter b. A radiation shield/condensation tray m is mounted under the burner tray. This prevents overheating of the floor surface under the water heater and serves as a collection tray for condensate.

The insulation layer h prevents heat loss. The inside of the hot water tank is enamelled to protect against corrosion. The anodes c provide additional protection.

2.3 The water heater’s

heating cycle

2.4 Protection for the

water heater

2.4.1 Water temperature protection

The water heater is controlled by the burner control q and the control thermostat t or frost thermostat w. The control thermostat and frost thermostat both independently measure the water temperature (T heating cycle is activated as soon as T value (T heater, see paragraph 6.2 Operating states. If the water heater is in the 'OFF mode' (frost protection), then this value is determined by the frost thermostat (threshold value = 20°C). If the water heater is in the 'ON mode', then the threshold value is selectable via the control thermostat (40°C - 70°C).

As soon as T close and the burner control will register a heat demand. The gas control n will open and the gas will mix with the air it draws in. This mixture is ignited by the hot surface igniter z and the water becomes heated. A soon as T T

set

burner control will stop the heating cycle.

The thermostats have a certain margin both when closing and opening. We refer to this margin as the hysteresis. The hysteresis cannot be adjusted.

The burner control monitors the water temperature by means of thermostats and ensures a safe combustion. This is achieved by:

•the Water temperature protection;

•the Combustion products discharge safety device;

•the flame probe.

By means of the frost, high-limit and safety thermostats, the burner control monitors three temperatures related to safety. Tab le 2 . 1 explains the operation of the thermostats with sensors.

). The value for T

set

falls below T

water

, the thermostat will open once more. The heat demand will cease and the

depends on the status chosen for the water

set

, the relevant thermostat (control or frost) will

set

falls below the specified threshold

water

). The water heater’s

water

exceeds

Tab le 2.1 Temperature protection

Protection Description

Frost thermostat If the frost thermostat sensor y detects a temperature of 20°C or lower, the

water heater’s heating cycle will start. See paragraph 2.3 The water heater’s

heating cycle.

High-limit thermostat If the high-limit thermostat sensor p detects a temperature greater than 84°C,

the high-limit thermostat will open. The heat demand will be stopped and the burner control will stop the heating cycle until the high-limit thermostat closes again. At that moment, the burner control resets the water heater and the heating cycle resumes. The high-limit safeguard serves to prevent overheating and/or excessive formation of scale in the water heater.

Safety thermostat If the safety thermostat sensor o detects a temperature greater than 93°C, the

safety thermostat will open. The heat demand will be ended and the burner control immediately stops the heating cycle. A lockout error will occur in the burner control. This must be manually reset, before the water heater can be put back into operation.

Instruction manual DR-LA 13

2.4.2 Combustion products discharge safety device

2.4.3 flame probe

2.5 Safety of the installation

Functioning of the water heater

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The flue gases are channelled to the outside via the draught diverter b and the flue gas discharge a. To prevent the flue gases from flowing back into the boiler room, the discharge ducting is monitored by a feature called the combustion products discharge safety device. This uses a flue gas thermostat f with flue gas thermostat sensor g which are located in the draught diverter. Under normal circumstances this sensor will register the ambient temperature. However, if the chimney is not drawing sufficiently (for example, due to a blockage in the chimney), the flue gases will flow back past the flue gas thermostat sensor. The sensor will then detect an excessive temperature and the flue gas thermostat will open. The heat demand will be ended and the burner control immediately stops the heating cycle. The flue gas thermostat will also lock out. This must be manually reset, before the water heater can be put back into operation.

To ensure that no gas can flow when there is no combustion, an flame probe A has been fitted. The burner control uses this rod for flame detection, by means of ionisation sensing. The burner control closes the gas valve as soon it detects that gas is flowing and there is no flame.

2.5.1 Unvented installation

With an unvented installation, an expension valve and expansion vessel prevent excessive pressure in the water heather. This prevents damage of the water heater. A non-return valve prevents excessive pressure in the water supply system. This valve also prevents water from flowing backwards from the heater into the cold water supply system. The pressure reducing regulates the water supply pressure to a normal operating pressure of 3.5 bar. The components are fitted to the cold water pipe. See paragraph 3.6.1 Cold water side.

2.5.2 Vented installation

With a vented installation, excess pressure is taken up by the open water tank. The level of the water determines the working pressure which may not exceed 8 bar.The installation must also be fitted with an open vent from the hot water pipe. Ideally the vent pipe should be linked to a separate tundish/drain or else to the cold water storage tank. A safety valve should also be fitted to the water heather. See paragraph 3.6.3 Hot water side.

2.5.3 Temparature and Pressure valve (T&P valve)

A T&P valve is mandatory in an 'unvented' installation.

A T&P valve monitors the water pressure in the water heater and the water temperature at the top of it. If the pressure in the water heater becomes excessive (> 7 bar) or the water temperature is too high (>97°C), the valve will open. The hot water will immediately flow out of the heater. Because the water heater is under water supply pressure, cold water will automatically flow into it. The valve remains open until the unsafe situation has been averted. A connecting point for a T&P valve is standard on the water heater. See paragraph

3.6.3 Hot water side.

2.6 Indicators and Alarms

2.6.1 Volt Free Contacts

Volt free contacts are supplied as standard to give remote indication/alarm of 'normal run' and 'lockout'. The 'lockout' indication includes shut down due to operation of the safety thermostat, loss of flame and failure to ignite.

14 Instruction manual DR-LA

Options

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2.7 Options The heaters can be supplied with the following additional variations, either

ready fitted or for site fitting:

2.7.1 LPG

The heaters can be supplied adjusted for use on propane or butane, see section

3.12. It is most important that the heater is correctly adjusted for the gas to be fired.

2.7.2 Unvented Supply

The heaters can be supplied with a purpose designed and sized unvented kit comprising pressure reducing valve, non-return valve, expansion vessel, expansion relief valve and pressure/temperature relief valve, to enable the heater to be coupled directly to the mains water. For details see 2.5.1, 2.5.3 and

3.6.

2.7.3 Top to Bottom Circulation

In order to give enhanced temperature control to aid compliance with the HSE guidance and the DHss Code of Practice for 'The Control of Legionellae in Health Care Premises', a pump circulation kit can be supplied comprising 230 volt single phase pump, non-return valve, pipe work and sufficient fittings to contact between the hot water flow and the bottom connection. For details see section 3.5 of this manual.

Instruction manual DR-LA 15

Functioning of the water heater

gis

16 Instruction manual DR-LA

Introduction

3 Installation

Warning

The installation should be carried out by an approved installation engineer in compliance with the general and local regulations imposed by the gas, water and power supply companies and the fire service.

The water heater may only be installed in a room which complies with the requirements stated in national and local ventilation regulations.

Refer also to paragraph 1.3 Regulations and documents.

3.1 Introduction This chapter describes the installation activities to be carried out before the

water heater may be started up, namely:

• Packaging;

• Environmental conditions;

• Technical specifications;

• Water connections, Unvented;

• Water connections, Vented;

• Gas connection;

• Flue gas discharge;

• Electrical connection;

• Checking the supply pressure and burner pressure;

• Conversion to a different gas category.

n Caution

Starting up the water heater is described in chapter 7 Starting up and

shutting down.

3.2 Packaging To avoid damaging the water heater, remove the packaging carefully. We

recommend unpacking the water heater at or near its intended location.

cNote

The water heater may only be manoeuvred in an upright position. Take care that the water heater is not damaged after unpacking.

3.3 Environmental

conditions

cNote

The water heater may not be used in rooms where chemical substances are stored or used due to the risk of explosion and corrosion to the water heater. Some propellants, bleaching agents, degreasing agents etc. disperse vapours which are explosive and/or which cause accelerated corrosion. If the water heater is used in a room in which such substances are present, the warranty will be void.

DR-LA water heaters are open water heaters and may only be placed in an open boiler room. They fall under category B

11B S

Instruction manual DR-LA 17

Installation

3.3.1 Humidity and ambient temperature

The boiler room must be frost-free or be protected against frost. Ta bl e 3 .1 shows the environmental conditions that must be adhered to, for correct functioning of the electronics present in the water heater to be guaranteed.

Table 3 .1 Humidity and ambient temperature specifications

Humidity and

Humidity max. 93% RH at +25°C

Ambient temperature Functional: 0 ≤ t ≤ 60°C

3.3.2 Maximum floor loading

In connection with the water heater’s weight, take account of the maximum floor loading, see Tab le 3 . 2.

Table 3 .2 Weight specifications related to maximum floor loading

Weight of the water heater filled with water

DR-LA 30 DR-LA 40 DR-LA 45 DR-LA 60 DR-LA 75 DR-LA 95 DR-LA 110

538 kg 611 kg 539 kg 613 kg 553 kg 543 kg 594 kg

3.3.3 Working clearances

For access to the water heater it is recommended that the following clearances are observed (see Figure 3.2):

• AA: around the water heater’s control column and cleaning openings: 100 cm.

• BB: around the water heater itself: 50 cm.

• Above the water heater (room to replace the anodes):

- 100 cm if using fixed anodes or

- 50 cm if using flexible anodes.

ambient temperature

18 Instruction manual DR-LA

Environmental conditions

If the available clearance is less than 100 cm, flexible magnesium anodes may be ordered from Hamworthy, the installation engineer / supplier.

n Caution

When installing the water heater, be aware that any leakage from the it and/ or connections can cause damage to the immediate environment or floors below the level of the boiler room. If this is the case, then the water heater should be installed above a wastewater drain or in a suitable metal leak tray. The leak tray must have an appropriate wastewater drain and must be at least 5 cm deep with a length and width at least 5 cm greater than the diameter of the water heater.

Figure 3.1 Working clearances

IMD-0135a

Instruction manual DR-LA 19

Installation

3.4 Technical specifications

The water heater is supplied without accessories. Check the dimensions and other specifications for the accessories to be used, based on Figure 3.2 and

Tabel 3.5.

10”

37” 45”

Figure 3.2 Plan and elevation of the water heater

IMD-0135

20 Instruction manual DR-LA

Technical specifications

Tab le 3.3 Dimensions

Dimension Description DR-LA30DR-LA40DR-LA45DR-LA60DR-LA75DR-LA95DR-LA

110

A Height including draught diverter (mm) 1900 2105 1900 2105 2010 2085 2085

B Height excluding draught diverter (mm) 1750 1960 1750 1960 1795 1870 1870

D Diameter of the water heater (mm) 710 710 710 710 710 710 710

E Width of water heater incl. draught diverter

(mm)

F Width including control column (mm) 1050 1050 1050 1050 1105 1105 1105

G Flue gas outlet diameter (mm) 150 150 180 180 225 225 225

J Height flue gas discharge (mm) 1840 2050 1840 2050 1935 2010 2010

K Height of the gas connection (mm) 205 205 205 205 205 205 200

M Height of the cold water supply (mm) 565 565 565 565 575 650 650

N Height of the hot water outlet (mm) 1605 1810 1605 1810 1640 1715 1715

P Height of the cleaning opening centre (mm) 770 770 770 770 780 855 855

R Height of the drain valve centre (mm) 500 500 500 500 520 595 595

S Height of the T&P plug centre (mm) 1550 1755 1550 1755 1585 1660 1660

1 Cold water supply connection (external

thread)

2 Hot water outlet connection (internal thread) Rp 11/

3 Gas control connection (internal thread) Rp ¾ Rp 1

4 Drain valve connection (internal thread) Rp 1½

5 T&P valve connection (internal thread) 1" NPT Rp 1½

1050 1050 1050 1050 1105 1105 1105

R 1

6 Dimensions of the cleaning and inspection

openings (mm)

Tab le 3.4 General and electrical data

DESCRIPTION Unit DR-LA30DR-LA40DR-LA45DR-LA60DR-LA75DR-LA95DR-LA

Storage capacity litres 324 374 312 351 291 265 264

Maximum operating pressurebar 8888888

Maximum operating pressure unvented

Nominal operating pressure unvented

Empty weight kg 214 237 227 262 262 278 330

Heating time ∆T=45

Number of anodes - 2223344

Number of bar burners/orifices- 3457796

Number of flue tubes/flue baffles- 5679121617

C minutes 32 28 20 16 13 9 7

bar 5,5 5,5 5,5 5,5 5,5 5,5 5,5

bar 3,5 3,5 3,5 3,5 3,5 3,5 3,5

Ø 100

110

Instruction manual DR-LA 21

Installation

Table 3 .4 General and electrical data (Continued)

DESCRIPTION Unit DR-LA30DR-LA40DR-LA45DR-LA60DR-LA75DR-LA95DR-LA

110

Electrical power consumption W 30 60

Supply voltage VAC 230 (-15% +10%)

Mains frequency Hz 50 (±1 Hz)

22 Instruction manual DR-LA

Tab el 3.5 Gas data

Technical specifications

Gas category data

2H3+

Data for natural gas 2H: G20-20 mbar

Orifice diameter mm 3.20 3.20 3.10 2.95 3.20 3.20 3.90

(1) = Blanking plate (2) = Burner pressure regulator (3) = High Low control

Nominal load (gross) KW 41.4 55.5 65.2 81.0 96.4 124.2 140.5

Nominal output KW 31.7 42.0 49.3 61.2 72.9 93.9 107.5

Supply pressure mbar 20 20 20 20 20 20 20

Burner pressure mbar 8.5 8.5 8.5 8.5 8.5 8.5 8.5

Gas consumption

Data for LP gas 3+

General

Orifice diameter mm 1.70 1.70 1.70 1.50 1.70 1.70 2.25

G30-30 mbar (butane)

(1) = Blanking plate (2) = Burner pressure regulator (3) = High Low control

(1)

Unit DR-LA30DR-LA40DR-LA45DR-LA60DR-LA75DR-LA95DR-LA

110

1, 2 or 32222222

m3/h 4.0 5.4 6.3 7.8 9.4 12.1 13.7

1,2, or 31111113

Nominal load (gross) kW 40.9 54.2 66.9 79.2 94.3 121.2 135.7

Nominal output kW 32.0 42.0 51.8 61.4 73.1 93.9 106.4

Burner pressure

Gas consumption

G31-37 mbar (butane)

Orifice diameter mm 1.70 1.70 1.70 1.50 1.70 1.70 2.25

(1) = Blanking plate (2) = Burner pressure regulator (3) = High Low control

Nominal load (gross) kW 37.6 50.1 62.1 76.2 87.8 110.9 127.6

Nominal output kW 29.4 38.7 48.0 58.9 67.9 85.7 99.8

Burner pressure

Gas consumption

(1) Based on 1013.25 mbar and 15oC. (2) If using a blank plate or high-low control program, instead of a burner pressure regulator, it is assumed that the burner pressure is equal

to the supply pressure. In practice however, the burner pressure will be lower.

(2)

(1)

mbar 30 30 30 30 30 30 30

kg/h 3.0 4.0 5.0 5.8 7.0 9.0 10.1

1,2, or 31111113

mbar 37 37 37 37 37 37 37

kg/h 2.7 3.7 4.5 5.3 6.4 8.1 9.3

Instruction manual DR-LA 23

Installation

3.5 Installation diagram Figure 3.3 shows the water and gas connection diagrams for unvented and

vented installations. The following paragraphs, describing the connections in detail, make reference to these diagrams

Legend

a pressure-reducing valve

(mandatory )

b expansion vessel (mandatory) c T&P valve (mandatory)

ca) safety valve d stop valve (recommended) e non-return valve (mandatory)

ea) non-return valve f circulation pump (optional) g drain valve h manual gas valve (mandatory) i stop valve (mandatory) j temperature

gauge (recommended)

k top to bottom recirculation

pump (optional)

l draught diverter m hot water draw-off points n expension valve (mandatory) o water tank p float valve q 3-way venting valve (optional) r overflow pipe

a cold water supply

b hot water outlet

c circulation pipe

d gas supply

e flue gas discharge

UNVENTED

VENTED

IMD-0142

IMD-0141

Figure 3.3 Installation diagrams

24 Instruction manual DR-LA

3.6 Water connections, Unvented

3.6.1 Cold water side

3.6.2 Top to bottom recirculating pump

Water connections, Unvented

See a in Figure 3.3.

1. Fit an approved stop valve regulations. Refer also to paragraph 1.3 Regulations and documents.

2. The maximum working pressure of the water heater is 8 bar. The expansion valve regulates the pressure to 5.5 bar. The operatiing pressure is 3.5 bar. Fit an approved pressure-reducing valve

3. Fit a non-return valve

4. Fit an expension valve

You can connect a top to bottom recirculation pump to prevent stratification of the water in the water heater.

1. Fit a pipe (Ø 22 mm), a stop valve

pump

2. Fit non-return valve

3. Fit stop valves

i on the cold water side as required by

e and an expansion vessel b.

n and connect the discharge to a drain via tundish.

d and a top to bottom recirculation

3.6.3 Hot water side

See b in Figure 3.3.

n Caution

Insulating long hot water pipes prevents unnecessary energy loss.

1. Optional: fit a temperature gauge the tap water.

2. Fit the T&P valve

3. Fit a stop valve

i in the hot water outlet pipe, for use when servicing.

3.6.4 Drain valve

1. Fit the standard drain valve supplied g.

2. If a circulation pipe is to be fitted, then refer to paragraph 3.6.5. Otherwise, fit the sealing nut and gasket supplied with the drain valve. See Figure 3.4.

3.6.5 Circulation pipe

See c in Figure 3.3. and Figure 3.4.

If an immediate flow of hot water is required at draw-off points, a circulation pump can be installed. This improves comfort and reduces water wastage.

1. Fit a circulation pump of the circulation system.

2. Fit a non-return valve direction of circulation.

3. Fit two stop valves for servicing

4. Connect the circulation pipe to the T-piece on the drain valve

Figure 3.4.

f of the correct capacity for the length and resistance

ea downstream the circulation pump to guarantee the

j to be able to check the temperature of

g. See

IMD-0122

Figure 3.4 Drain valve

Instruction manual DR-LA 25

3.7 Water connections, Vented

3.7.1 Cold water side

3.7.2 Top to bottom recirculating pump

3.7.3 Hot water side

Installation

See a in Figure 3.3.

• Fit an approved stop valve

tank o and the water heater, as required by regulations. Ideally the vent pipe should be linked to a separate tundish/drain or else to the cold water storage tank. Refer also to paragraph 1.3 Regulations and documents.

You can connect a top to bottom recirculation pump to prevent stratification of the water in the water heater.

1. Fit a pipe (Ø 22 mm), a stop valve pump

2. Fit non-return valve

3. Fit stop valves

See b in Figure 3.3.

i on the cold water side between the water

d and a top to bottom recirculation

3.8 Gas connection

n Caution

Insulating long hot water pipes prevents unnecessary energy loss.

1. Fit a safety valve

2. Optional: fit a temperature gauge the tap water.

3. Fit a stop valve

4. If a circulation pipe is to be fitted, then refer to paragraph 3.7.4.

3.7.4 Circulation pipe

See c in Figure 3.3.

If an immediate flow of hot water is required at draw-off points, a circulation pump can be installed. This improves comfort and reduces water wastage.

1. Fit a circulation pump of the circulation system.

2. Fit a non-return valve direction of circulation.

3. Fit two stop valves for servicing

4. Connect the circulation pipe to the T-piece on the drain valve

Figure 3.4.

Warning

Gas installation may only be carried out by an authorised installation engineer in compliance with the general regulations imposed by the gas company. Refer also to paragraph 1.3 Regulations and documents.

ca.

j to be able to check the temperature of

i in the hot water outlet pipe, for use when servicing.

f of the correct capacity for the length and resistance

ea downstream the circulation pump to guarantee the

g. See

cNote

Make sure that the diameter and length of the gas supply pipe are large enough to supply sufficient capacity to the water heater.

26 Instruction manual DR-LA

3.9 Flue gas discharge

3.9.1 Introduction

Flue gas discharge

See d in Figure 3.3.

1. Fit a gas valve

2. Blow the gas pipe through before use, to be sure it is clean.

3. Close the gas valve.

4. Fit the gas supply pipe to the gas control.

h in the gas supply pipe.

Warning

Check for leaks after fitting.

Warning

The installation should be carried out by an authorised installation engineer, in compliance with the general and local regulations imposed by gas, water supply and power supply companies and the fire service. Refer also to paragraph 1.3 Regulations and documents.

When connecting the water heater to the chimney, the draught diverter l supplied with the water heater must be used. The standard flue gas thermostat and sensor that are supplied must be fitted in the draught diverter.

3.9.2 Fitting the draught diverter

Legend

a sealing ring b fastening screws c chimney pipe d 45° bend e holes to attach support bracket f support bracket

n Caution

To guarantee draught a chimney pipe with a lenght of at least 0.5 m should be fitted to the 45o bend.

The draught diverter can be positioned according to preference. After positioning, the draught diverter is secured using two screws b to the top surface of the water heater and also sits on a support bracket side of the water heater. The assembly procedure is as follows:

> 0.5 m

f attached to the

a b

Figure 3.5 Placing the draught diverter

IMD-0123

1. Take the support bracket out of the bag.

2. Fit the support bracket diverter.

3. Drill two holes

4. Screw the support bracket tightly to the water heater.

e (3.2 mm drill) for the support bracket screws.

f in such a way that it properly supports the draught

Instruction manual DR-LA 27

Installation

5. Place the draught diverter in the support bracket and mark the centres for the two drill holes on the top surface of the water heater. Remove the draught diverter from the water heater.

6. Now drill two holes

7. Place the sealing ring

8. Screw the draught diverter tightly in place.

9. Fit:

- a 45° bend

- a corrosion-resistant vertical chimney pipe

- the remaining flue components.

n Caution

Use flue gas discharge materials that comply with the regulations. See paragraph 1.3 Regulations and documents.

n Caution

Make sure that the chimney discharges into an area where this is permitted for this category of water heater.

b into the top of the water heater (3.2 mm drill).

a on the water heater.

d onto the outlet of the draught diverter, followed by:

c of at least 0.5 metre,

3.9.3 Flue gas thermostat assembly

Attached to the control column is a plastic bag containing the flue gas thermostat with sensor and related attachment materials. The cable from the sensor is already connected in the control column. The thermostat/bracket and sensor have yet to be fitted inside the draught diverter. See Figure 3.6.

Warning

If the flue gas thermostat is not (or is incorrectly) fitted/connected, the flue gas discharge will not be protected. An incorrectly fitted chimney can cause flue gases to backflow into the boiler room.

Figure 3.6 Flue gas thermostat assembly

Fit the flue gas thermostat as follows:

1. Take the bracket 1 with thermostat and sensor 2 from the packaging.

2. Place the bracket in the draught diverter and screw the bracket and the sensor firmly in place.

3. Bend the cable clips 3 around the cable 4 of the flue gas thermostat.

28 Instruction manual DR-LA

IMD-0137.

3.10 Electrical connection

4. Screw the cable clips 3 in place in the draught diverter and the water heater.

Warning

3.10.1 Introduction

Topics covered in this paragraph:

• 3.10.2 Preparation;

• 3.10.3 Mains power;

3.10.2 Preparation

cNote

The water heater is phase-sensitive. It is absolutely essential to connect the phase (L) from the mains to the phase of the water heater and the neutral (N) of the mains to the neutral of the water heater. There should also be no potential difference present between neutral (N) and earth ( applied in the supply circuit. For more information or to order this isolating transformer, please contact Hamworthy.

Electrical connection

A). If this is the case, then an isolating transformer must be

Figure 3.7 shows a front view of the electrical connection block. Ta bl e 3 . 6

shows the associated connections.

Tab le 3.6 Electrical connection block DR-LA

Mains power Combustion products

discharge safety device

123 4 5 6789101112

Close Control

Thermostat

A L

Time clock power Corex Anode

Volt Free contact

Lock Out

NO P NC NO P NC

power

Volt Free contact

Normal Run

Time clock

connection

A NL N L NLNLL LL

13 14 15 16 17 18 19 20 21 22 23 24

Instruction manual DR-LA 29

Installation

Figure 3.7 Connection block (connections 1 through 6 explained in Ta bl e 3 .6 )

In preparation, first remove the protective cover from the control column:

• Undo the 4 screws 1 and remove the protective cover 2 from the electrical section. The connection block 3 is now visible.

IMD-0134

n Caution

Refer to 1.2 Electrical diagram DR-LA for the connection of electrical components.

3.10.3 Mains power

The water heater is supplied without a power cable and isolator.

n Caution

In order to receive electrical power, the water heater has to be connected to the mains voltage by means of a permanent electrical connection. A double pole isolator with contacts gaps of at least 3 mm must be fitted local to the water heater. The power cable must have cores of at least 3 x 1.0 mm2.

1. Feed the power cable through the metric strain relief on the top of the control column.

2. Connect earth (A), phase (L1) and neutral (N) on the power cable to terminals 1 to 3 of the connection block as set out in Table 3.6.

3. Tighten the strain relief so that the cable is clamped.

4. If you do not need to make any more connections, then fit the protective cover back on the control column.

30 Instruction manual DR-LA

3.11 Checking the supply pressure and burner pressure

Checking the supply pressure and burner pressure

5. Connect the power cable to the isolator.

Warning

Leave the water heater disconnected until you are ready to start it up.

cNote

Before you start up the water heater and/or begin to check the supply pressure and burner pressure, you must first fill the water heater. Please refer to paragraph 4.2 Filling the water heater for filling instructions.

cNote

Before starting-up for the first time and following conversion, you must always check the supply pressure and burner pressure. If necessary, adjust these to be certain of optimum performance of the water heater.

cNote

The easiest way to check the gas pressures is by using two pressure gauges. This procedure assumes that these two gauges are available.

Legend

a burner pressure regulator b burner pressure regulator

cap

c burner pressure regulator

adjusting screw

d gas control connector e blank plate f supply pressure test nipple g gas control h manifold test nipple i high-low control

Gas control valve for DR-LA 30 to 95

Figure 3.8 Gas control valve for DR-LA 30 through 95 and DR-LA 110

Instruction manual DR-LA 31

IMD-0127

Installation

Gas control valve for DR-LA 110

a i

IMD-0129

Figure 3.8 Gas control valve for DR-LA 30 through 95 and DR-LA

To check the supply pressure and burner pressure, proceed as follows:

1. Disconnect the water heater from the power supply. See paragraph

7.3.2 Isolate the water heater from the power supply.

2. On the gas control (Figure 3.8) there are two test nipples. To check the supply pressure, test nipple control is not used. The manifold test nipple h is used for measuring the burner pressure. Sealing screws are located inside the test nipples. Loosen both sealing screws by a few turns. Do not loosen them completely; this makes them difficult to tighten again.

3. Connect a pressure gauge to the manifold test nipple

f is used. The other test nipple on the gas

n Caution

All gas pipes should be bleeded and free of leakage.

4. Connect a pressure gauge to test nipple.

5. Open the gas supply .

6. Switch on the power to the water heater using the isolator on the water heater.

7. Set the control thermostat to the highest position and start the water heater running by putting the On/Off-switch to position I.

8. The heating cycle will start and the burner tray will ignite after a short time.

9. After the burner tray has ignited, wait for approximately 1 minute before you start reading the dynamic pressures.

10. Use the pressure gauge to read the supply pressure at the test nipple Refer to Tabel 3.5.

n Caution

Consult the mains gas supply company if the supply pressure is not correct.

32 Instruction manual DR-LA

Conversion to a different gas category

11. Use the pressure gauge to read the burner pressure at test nipple h. Refer

to Ta be l 3 .5 .

n Caution

If the burner pressure is not correct and the water heater is fitted with a blank plate or high-low control, you will not be able to adjust the pressure. In this case, consult your installation engineer or supplier. If the water heater is fitted with a burner pressure regulator, then the pressure can be adjusted by following steps 12 through 17.

3.12 Conversion to a different gas category

12. Remove the cap

13. Adjust the burner pressure by turning the adjusting screw the correction required:

- Adjusting screw anticlockwise: burner pressure decreases.

- Adjusting screw clockwise: burner pressure increases.

14. Cover the opening of the adjusting screw and check the burner pressure against the target value from Tabel 3.5.

15. If the pressure reading is not correct, repeat steps 13 and 14 until the correct pressure is attained.

16. Fit the cap

17. Shut down the water heater by putting the On/Off -switch to position 0.

18. Shut off the gas supply.

19. Disconnect the two pressure gauges and re-tighten the sealing screws in the test nipples.

cNote

The conversion may only by carried out by an authorised installation engineer.

3.12.1 Introduction

If the water heater must operate on a family of gas (LP-gas or natural gas) other than the category of gas for which the water heater has been set up at the factory, the water heater will have be adapted using a special conversion kit.

b from the burner pressure regulator a.

c, depending on

b on the burner pressure regulator.

cNote

After conversion, check the supply pressure and the burner pressure.

There are differences between the conversions for the DR-LA 110 and the DRLA 30 through 95. The conversion procedures are described in paragraphs:

• 3.12.2 Conversion to a different gas category DR-LA 30 through 95

• 3.12.3 Conversion to a different gas category, DR-LA110.

Instruction manual DR-LA 33

Legend

a cover plate b locking strips c orifice with stamped figures

Installation

3.12.2 Conversion to a different gas category DR-LA 30 through 95

Take care

The burner may be hot.

IMD-012

Figure 3.9 Exchanging orifices

1. Disconnect the water heater from the power supply. See paragraph

7.3.2 Isolate the water heater from the power supply.

2. Shut off the gas supply.

3. Unscrew the cover plate

4. Use a suitable tool to remove the locking strips have very sharp edges. Withdraw the locking strips straight upwards.

5. The radiation shield / the condensation tray can be temporarily loosened to simplify assembly of the burner.

6. Remove the burners one by one from their brackets at the front. To do this, you first move them away from you and then downwards. The orifices will now be accessible.

7. Remove the orifices.

8. Select and fit the correct orifices from the conversion kit, based on Tabel 3.5. The orifice diameter is indicated by figures stamped on the orifice, see

9. Refit the burners back in their original position.

10. Re-fit the locking strips.

11. If the radiation shield / the condensation tray was loosened, re-tighten it.

a from the burner support.

b. Note: the locking strips

34 Instruction manual DR-LA

Legend

See Figure 3.9 for

d burner pressure regulator e gas control connector f blank plate g supply pressure test nipple h gas control valve

a through c.

Conversion to a different gas category

Figure 3.10 Conversion of gas control

12. Check whether there is a burner pressure regulator d fitted to the gas

n Caution

13. If the blank plate or burner pressure regulator need to be replaced:

cNote

14. Check the burner pressure and supply pressure (see paragraph 3.11).

15. Remove the sticker showing the new gas category from the conversion kit

control or simply a blank plate

In the event the supply pressure for a gas category is the same as the burner pressure (see Tabel 3.5) then the gas control must be fitted with a blank plate with cork gasket. A burner pressure that deviates in comparison to the supply pressure requires the use of a burner pressure regulator with rubber gasket. Each conversion kit contains all the necessary components.

- Unscrew the connector

- Either, remove the blank plate

- Either, fit the blank plate or burner pressure regulator supplied with the conversion kit.

- Refit the connector

and attach it below the water heater’s rating plate. This clearly indicates that the water heater may no longer be run on the gas for which it was originally supplied.

e from the gas control.

f or burner pressure regulator d.

e to the gas control.

IMD-0131

Instruction manual DR-LA 35

3.12.3 Conversion to a different gas category, DR-LA110

Legend

a burner pressure regulator b high-low control c gas control valve

Installation

16. Start the water heater (see paragraph 7.2).

Introduction

This paragraph describes the:

• Conversion from LP gas to natural gas.

• Conversion from natural gas to LP gas.

1 2

Figure 3.11 Conversion of gas control DR-LA110

Conversion from LP gas to natural gas

1. Perform steps 1 through 9 of paragraph 3.12.2 Conversion to a different gas

category DR-LA 30 through 95.

2. Detach the high-low control

3. Fit the burner pressure regulator a including the sealing gasket from the conversion kit. Attach the burner pressure regulator to the gas control

c using the two small screws supplied.

valve

IMD-0132

36 Instruction manual DR-LA

Legend

Conversion to a different gas category

See Figure 3.11 for numbers 1 through 3.

d timers e bracket f 6-terminal connector strip g pull reliefs h 9-terminal connector strip i metric strain relief j high-low control cable

IMD-0130

Figure 3.12 Fitting and removal of conversion components

4. Detach the cables between the 6-terminal connector strip 6 and the 9-terminal connector strip 9. These are the cables for the timers, high-low control, gas control, hot surface igniter and flame probe.

5. Remove the timers 4, bracket 5, cable harness (not shown) and 9-terminal connector strip 8.

6. Turn the metric strain relief 9 with the high-low control cable 0 to loosen it. Remove this cable.

7. Fit the stop plug from the conversion set in the place of the metric strain relief.

8. Connect the cables of the gas control valve, the hot surface igniter and flame probe to the 6-terminal connector strip as shown in the electrical diagram. See appendices 1.2.1 Electrical diagram DR-LA 30 through 95 and 110

(natural gas) and 1.2.2 Electrical diagram DR-LA 110 (LP gas).

Instruction manual DR-LA 37

Installation

9. Clamp the gas control cable in one of the pull reliefs supplied 7. Do the same for the cables from the hot surface igniter and flame probe.

cNote

10. Check the burner pressure and supply pressure (see paragraph 3.11).

11. Remove the sticker showing the new gas category from the conversion kit and attach it below the water heater’s rating plate. This clearly indicates that the water heater may no longer be run on the gas for which it was originally supplied.

12. Start the water heater (see paragraph 7.2)

Conversion from natural gas to LP gas

1. Perform steps 1 through 9 of paragraph 3.12.2 Conversion to a different gas

category DR-LA 30 through 95.

2. Detach the burner pressure regulator

3. Fit the high-low control kit. Attach the high-low control to the gas control using two small screws.

4. Detach the cables from the gas control valve, the hot surface igniter and the flame probe from the 6-terminal connector strip 6 and the strain relief 7.

5. Fit the timers 4 including cable harness plus 9-terminal connector strip 6 from the conversion kit, to the control column.

6. Remove the stop plug (not shown) from the underside of the control column and replace this with the metric strain relief 9 from the conversion kit.

7. Draw the high-low control cable 0 through the strain relief and tighten the strain relief by turning it until the cable is clamped.

8. Connect the high-low control cable 0 plug to the high-low control

9. Connect the cables from the timers, high-low control, gas control, flame probe and the hot surface igniter as shown in the electrical diagram. See appendix 1.2 Electrical diagram DR-LA.

b including the sealing gasket from the conversion

cNote

10. Check the burner and supply pressure (see paragraph 3.11).

12. Start the water heater (see paragraph 7.2).

38 Instruction manual DR-LA

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4 Filling and draining

4.1 Introduction Topics covered in this chapter:

• Filling the water heater.

• Draining the water heater.

The components referred to in these paragraphs are illustrated in Figure 4.1.

Legend

a pressure-reducing valve

(mandatory )

b expansion vessel (mandatory)

c T&P valve (mandatory)

ca) safety valve

d stop valve (recommended)

e non-return valve (mandatory)

ea) non-return valve

f circulation pump (optional)

g drain valve

h manual gas valve (mandatory)

i stop valve (mandatory)

j temperature

gauge (recommended)

k top to bottom recirculation

pump (optional)

l draught diverter

m hot water draw-off points

n expension valve (mandatory)

o water tank p float valve

q 3-way venting valve (optional)

r overflow pipe

a cold water supply

b hot water outlet

c circulation pipe

d gas supply

e flue gas discharge

UNVENTED

VENTED

Introduction

IMD-0142

Figure 4.1 Installation diagrams

Instruction manual DR-LA 39

4.2 Filling the water heater

Filling and draining

gis

4.2.1 Filling unvented installations

To fill the water heater, proceed as follows.

1. Open the stop valve i in the hot water pipe and, if present, the stop valves d for the circulation pump.

2. Shut drain valve g.

3. Open the nearest hot water draw-off point m.

4. Open the supply valve i on the cold water side a so that cold water flows into the water heater.

5. Completely fill the water heater (when cold water flows at normal pressure from the nearest hot water draw-off point, the water heater is full).

6. Vent the entire installation of air, for example by opening all hot water drawoff points.

7. The water heater is now under water supply pressure. There should be no water coming out of the expansion valve n nor the T&P-valve c. If this does happen, the cause might be:

- The water supply pressure is greater than the specified 3.5bar.

Check the correct pressure.

- The expansion valve in the protected cold supply setup is defective or

incorrectly fitted.

4.2.2 Filling vented installations

4.3 Draining the water heater

4.3.1 Draining unvented installations

To fill the water heater, proceed as follows.

1. Open the stop valve i in the hot water pipe and, if present, the stop valves d for the circulation pump.

2. Shut drain valve g.

3. Open the nearest hot water draw-off point m.

4. Open the supply valve i on the cold water side a so that cold water flows into the water heater.

5. Completely fill the water heater (when cold water flows at normal pressure from the nearest hot water draw-off point, the water heater is full).

6. Vent the entire installation of air, for example by opening all hot water drawoff points.

7. The water heater is now under water supply pressure. There should be no water coming out of the T&P-valve ca. If this does happen, the safety valve might be defective or incorrectly fitted.

Some service activities require the water heater to be drained. The procedure is as follows:

1. Shut the water heater down by putting the On/Off switch to position 0.

2. Disconnect the water heater by putting switching the mains isolator off.

3. Shut off the gas supply h.

4. Close the stop valve i in the hot water pipe.

5. Close the supply valve in the cold water supply a.

6. Open the drain valve g.

40 Instruction manual DR-LA

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Draining the water heater

7. Vent the water heater (or installation) so that it drains completely.

4.3.2 Draining vented installations

Some service activities require the water heater to be drained. The procedure is as follows:

1. Shut the water heater down by putting the On/Off switch to position 0.

2. Switch the mains isolation off.

3. Shut off the gas supply h.

4. Close the stop valve i in the hot water pipe.

5. Close the stop valve between the water tank and the cold water inlet.

6. Open the drain valve g.

Instruction manual DR-LA 41

Filling and draining

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42 Instruction manual DR-LA

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5 Controls

5.1 Introduction Topics covered in this chapter:

• 5.2 Control panel;

• 5.3 Explanation of the symbols;

• 5.4 ON/OFF switch;

• 5.5 Control thermostat;

• 5.6 Burner control reset button;

• 5.7 Flue gas thermostat reset button.

5.2 Control panel Figure 5.1 shows the control panel The panel consists of:

• an ON/OFF switch;

• a reset button;

• a control thermostat with rotary knob;

• two status LEDs.

Introduction

IMD-0361

Figure 5.1 The control panel

Instruction manual DR-LA 43

Controls

gis

5.3 Explanation of the symbols

5.4 ON/OFF switch The ON/OFF switch is used to put the water heater in the ON mode or OFF

Table 5.1 shows the meanings of thesymbol s on the control panel.

Table 5 .1 Icons and their meaning

Symbol Name Explanation

ON/OFF switch 'ON mode' / 'OFF mode'

Reset button Reset burner control

Power LED Indicates power to burner control

Error LED Burner control lockout

Temperature control To set water temperature (T

mode. The water heater remains live, even when in the OFF mode. This ensures the frost protection remains activated.

set

)

n Caution

To electrically disconnect the appliance, you must use the main switch between the appliance and the mains power supply.

5.5 Control thermostat Use the rotary knob of the control thermostat to set the desired water

temperature to between 40°C and 70°C. The knob rotates over a scale of 1 to

4. Ta bl e 5 . 2 shows the temperatures corresponding to each position.

Table 5 .2 Temperature setting

Position Temperature

5.6 Burner control reset button

An error can cause the burner control to lock out. When this happens, the red LED on the control panel will illuminate. After eliminating the cause of the error, you can reset the water heater using the reset button.

≈ 40°C

≈ 50°C

≈ 60°C

≈ 70°C

n Caution

Before resetting, always eliminate the cause of the error.

To identify the various errors, refer to chapter 6 Status of the water heater. Chapter 8 Troubleshooting describes how to troubleshoot errors and problems.

5.7 Flue gas thermostat reset button

44 Instruction manual DR-LA

A malfunction in the flue gas discharge, e.g. a blockage in the chimney, can lead to the flue gas thermostat locking out. This state is evident when the push button on the flue gas thermostat has been activated, see Figure 5.2. Once the cause has been removed and the sensor has cooled down sufficiently, press this push

gis

Take care

The draught diverter can be hot.

Flue gas thermostat reset button

button to reset (if the sensor is not sufficiently cooled down, the flue gas thermostat will immediately lock out again). The water heater will then automatically start up again, if there is a demand. If this does not happen, refer to chapter 8 Troubleshooting for a complete troubleshooting guide.

Figure 5.2 Flue gas thermostat reset button

IMD-0140

Instruction manual DR-LA 45

Controls

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46 Instruction manual DR-LA

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6 Status of the water

heater

6.1 Introduction Topics covered in this chapter:

• 6.2 Operating states;

• 6.3 Error states;

6.2 Operating states The water heater has three operating states, namely:

• ISOLATED

In this state the water heater is off and all components are electrically dead. The isolator (switch between the water heater and the power supply) is turned off. On the control panel:

- the ON/OFF switch is at position 0;

- the green LED is off.

• OFF

In this state, the frost protection is activated. The isolator is set to position I. On the control panel:

- the ON/OFF switch is at position 0;

- the green LED is illuminated.

• ON

In this state the water heater continuously fulfils the demand for heat. On the control panel:

- the ON/OFF switch is at position I;

- The water temperature can be set by turning the rotary knob on the control thermostat, see paragraph5.5 Control thermostat;

- the green LED is illuminated.

Introduction

6.3 Error states If the water heater has an error the heater will not operate. The frost protection

will also be out of operation.

If the water heater should go into an "error" state, you will be unable to continuosly draw hot water. These error conditions are divided into three groups:

• Lockout error due to the flue gas thermostat The lockout (push button) of the flue gas thermostat in the draught diverter has been activated. See paragraph 5.7 Flue gas thermostat reset button. After removing the cause, the push button must be pressed to re-start the water heater.

• Lockout errors of the burner control In this event, the red error LED on the control panel will be illuminated. The burner control is locked out. After eliminating the cause. the water heater must be returned to service by pressing the reset button (see 5.6 Burner control reset button).

• Blocking error due to high limit thermostats You can recognise this status by the fact that the water heater will not start operation, despite the water temperature being lower than you have set with the control thermostat (see 5.5 Control thermostat). This error disappears automatically once the high limit thermostat resets itself, after which the water heater re-starts.

Instruction manual DR-LA 47

Status of the water heater

gis

The cause of the error cannot be seen on the control panel. For a detailed overview of error states, please refer to chapter 8 Troubleshooting.

If, as end-user, you find the water heater in an error status, you may attempt to re-start the water heater by pressing the reset button once. However, should the error return or become persistent, you should contact your service and maintenance engineer.

48 Instruction manual DR-LA

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7 Starting up and

shutting down

7.1 Introduction Topics covered in this chapter:

• Starting up;

• Shutting down;

• Heating cycle.

7.2 Starting up Start-up the water heater as follows:

1. Fill the water heater. See chapter 4 Filling and draining.

2. Open the manual gas valve (see Figure 4.1 Installation diagrams).

3. Switch on the power to the water heater using the isolator between the water heater and the power supply.

4. Switch the water heater to "ON mode" by switching the ON/OFF switch on the control panel to position I.

5. Set the desired water temperature using the control thermostat. See paragraph 5.5 Control thermostat

If there is a heat demand, the water heater will run through a heating cycle. See paragraph 7.4 Heating cycle.

Introduction

7.3 Shutting down You can:

• Shut the water heater down for brief periods ("OFF mode").

• Isolate the water heater from the power supply.

• Shut the water heater down for a longer period.

7.3.1 Shut the water heater down for brief periods ("OFF mode")

To shut the water heater down for a brief period, you must activate the frost protection. Refer also to paragraph 2.3 The water heater’s heating cycle

With the frost protection you can prevent water freezing in the water heater. Activate the frost protection by switching the ON/OFF switch on the control panel to position 0.

7.3.2 Isolate the water heater from the power supply

The water heater should only be isolated from mains power in the correct way. The correct procedure is as follows:

1. Shut the water heater down by switching the ON/OFF switch to position 0.

2. Disconnect the water heater by switching the isolator between the water heater and the mains power supply to position 0.

7.3.3 Shut the water heater down for a longer period

Drain the water heater, if you are shutting it down for a longer period of time. Proceed as described in paragraph 4.3 Draining the water heater.

Instruction manual DR-LA 49

Starting up and shutting down

gis

7.4 Heating cycle The heating cycle is activated as soon as the measured water temperature

) falls below the threshold value (T

water

the state in which you want to place the water heater. For example, if the water heater is in the "OFF mode" (frost protection), then this value is 20°C. If the water heater is in the "ON mode", then this threshold value is selectable, for example, position 3 (60°C).

The heating cycle runs in turn through the following states:

1. HEAT DEMAND;

2. WAITING TIME;

3. PRE-GLOW;

4. IGNITION;

5. RUNNING;

6. WAITING TIME.

The complete cycle is explained in the example set out below.

n Caution

The water heater runs through an identical cycle when frost protection is activated.

). This threshold value depends on

set

1. The control thermostat sensor measures the water temperature. The water temperature falls below the set temperature, e.g. 60°C, causing the control thermostat to close. The burner control now detects a heat demand and starts the heating cycle.

2. After heat demand is detected, the waiting time begins. This waiting time ensures the ignition takes place safely. The waiting time lasts about 15 seconds.

3. Once the waiting time is over (audible ’clicking’ of the relay in the burner control) the pre-glowing of the hot surface igniter is started

4. After about 12 seconds (pre-)glowing, the gas control is opened and ignition can take place.

5. After ignition, the flame is detected and the water heater will be running. This means that actual heating has started.

6. When the water is up to temperature, the heat demand cuts out. The gas control closes and the burner tray is extinguished. A new waiting time begins, of about 10 seconds.

7. After this waiting time, the water heater enters a state of rest and waits until the water temperature again falls below the set temperature.

With any subsequent heat demand, the heating cycle will resume from step 1.

50 Instruction manual DR-LA

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8 Troubleshooting

8.1 Introduction This chapter covers the following errors:

• Gas smell.

• Water leakage.

• Explosive ignition.

• Poor flame profile.

• No hot water

• Insufficient hot water.

If the water heater should go into an "error" state, you will be unable to draw hot water. These error conditions are divided into three groups:

• Lockout error due to flue gas thermostat The lockout (push button) of the flue gas thermostat in the draught diverter has been activated. See paragraph 5.7 Flue gas thermostat reset button. After removing the cause, the push button must be pressed to re-start the water heater.

• Blocking errors You can recognise this status by the fact that the water heater will not start operation, despite the water temperature being lower than you have set with the control thermostat (see 5.5 Control thermostat). These errors disappear automatically once the cause of the error has been removed, after which the water heater re-starts itself.

The following pages provide troubleshooting tables for each type of error.

n Caution

Footnotes referred to from within the tables are shown at the bottom of the last page of the table in question.

Instruction manual DR-LA 51

Warning

Maintenance may only be performed by a qualified service and maintenance engineer.

8.2 Troubleshooting table for general errors

Table 8 .1 General errors Page 1 of 2

Symptom Cause Solution Remark

Gas smell Gas leak

Water leakage Leakage from one of

the water connections (threaded).

Leakage from another nearby water heater or pipe segment.

Leakage from the water heater’s hot water tank.

Warning

Immediately close the main gas valve.

Warning

Do not operate any switches.

Warning

No naked flames.

Warning

Ventilate the boiler room.

Tighten the threaded connection. If the leak persists, consult your installer.

Trace the leak.

Consult the supplier and/or manufacturer.

n Caution

Immediately contact your installer or local gas company.

Condensation Before drawing off (too much) hot tap water, wait until the water in

the heater has reached the set temperature.

Instruction manual DR-LA 52

Warning

Maintenance may only be performed by a qualified service and maintenance engineer.

Table 8 .1 General errors Page 2 of 2

Symptom Cause Solution Remark

Explosive ignition

Poor flame profile

Incorrect supply pressure and/or burner pressure.

Contaminated burner Clean the burner. See 9.4.2 Cleaning the burners

Contaminated orifice. Clean the orifice. See 9.4.3 Cleaning the orifices

Inadequate air supply Improve the air supply by better ventilating the boiler room.

Set the correct supply pressure and/or burner pressure, see

3.11 Checking the supply pressure and burner pressure.

If ignition is not improved, consult your installer.

8.3 Troubleshooting table "no hot water"

If the water heater fails to supply any hot water, there are several possible causes. Refer to table Table 8.2 No hot water.

Table 8.2 No hot waterPage 1 of 2

Symptom Cause Solution Remark

Green LED OFF

and

Red LED OFF

Green LED ON

and

Red LED OFF.

No voltage from power supply

Blockage in the flue gas discharge (the combustion products discharge safety device has cut out)

1. Check that the isolator is ON.

2. Check the voltage across the isolator.

3. Check the voltage on the electrical connector block.

4. Check the voltage on the burner control.

5. Check the fuse in the burner control.

The measured voltage must be 230V AC +15% -10%.

1. Trace the blockage.

2. Remove the blockage.

3. Reset combustion products discharge safety device. See paragraph 5.7 Flue gas thermostat reset button.

See appendix 1.2 Electrical diagram DR-LA. If you cannot resolve the error, contact your installation engineer.

When heat demand is detected, the water heater will re-start.

Instruction manual DR-LA 53

Warning

Maintenance may only be performed by a qualified service and maintenance engineer.

Table 8.2 No hot waterPage 2 of 2

Symptom Cause Solution Remark

Green LED ON

and

Red LED ON.

There are three possible causes for this error. To determine the cause, the error must be made to recur:

1. Reset the water heater by pressing the reset button once;

2. Should nothing happen, then the reset button has already been pressed too often (maximum 5 times in a single heating cycle) and you will have to first electrically isolate the water heater, then start it again. See paragraph 7.3.2 Isolate the water heater from

the power supply and steps 3 through 5 of paragraph 7.2 Starting up.

3. Decide which type of cause (a) or (b) describes the situation.

(a) three unsuccessful start attempts in a row

(b) The safety thermostat has cut out

1. No gas:

• Check that the gas valve is open.

• Check that gas control opens (clicking of the gas control).

• Check the gas control wiring.

2. No ignition:

• Check whether the hot surface igniter lights up.

• Check the power supply to the hot surface igniter.

• Check the wiring of the hot surface igniter.

3. No flame detection:

• Check that the Phase (L) and Neutral (N) are correctly connected (from the power supply) to the water heater

• Check that the flame probe is not defective.

• Check that the wiring to the flame probe is correctly connected.

1. The safety thermostat has cut out correctly:

• Reset the water heater.

• Check whether the control thermostat is working.

• Check whether the high-limit thermostat is working.

• Check that the circulation pump (if present) is working.

2. The safety thermostat has cut out without apparent reason:

• Check whether the thermostat may be broken.

• Check whether the thermostat sensor may be broken.

If the error cannot be resolved or is persistent, contact your installer.

Instruction manual DR-LA 54

Warning

Maintenance may only be performed by a qualified service and maintenance engineer.

8.4 Troubleshooting table "insufficient hot water’"

If the water heater fails to supply any hot water, there are several possible causes. Refer to Table 8.3 Insufficient hot water

Table 8.3 Insufficient hot water

Symptom Cause Solution Remark

Insufficient hot water The water temperature

setting (T

Hot water supply used up.

) is too low

set

Set the control thermostat to a higher setting. See paragraph

5.5 Control thermostat.

1. Reduce the rate of hot water consumption. Allow the water heater enough time to heat up the water.

2. If this error occurs regularly, check whether the high-limit thermostat is cutting in/out. If so, check that the circulationand/or top to bottom recirculation pump are working properly.

If the error has not been rectified and no other cause can be found, isolate the water heater from the power supply, shut off the gas valve and alert your installer.

Instruction manual DR-LA 55

Warning

Maintenance may only be performed by a qualified service and maintenance engineer.

Instruction manual DR-LA 56

9 Maintenance

9.1 Introduction

Introduction

cNote

Maintenance may only by carried out by an approved service and maintenance engineer.

At each service, the water heater undergoes maintenance both on the water side and on the gas side. The maintenance should be carried out in the following order.

1. Preparing for maintenance;

2. Water-side maintenance;

3. Gas-side maintenance;

4. Finalising maintenance.

9.2 Preparing for maintenance

n Caution

Before ordering spare parts, take a moment to write down the water heater type and model and the full serial number of the water heater. Only by ordering with this information can you be sure to receive the correct spare parts. These details can be found on the rating plate.

To test whether all components are still working properly, you should complete the following steps:

1. Put the ON/OFF switch on the control panel to position 0.

2. Set the control thermostat (note the original setting) to the highest position and put the ON/OFF switch back to position I.

3. If there is no heat demand, draw some hot water off to initiate a heat demand.

4. Check whether the heating cycle runs correctly. See paragraph 7.4 Heating

cycle.

5. Set the control thermostat back to the original setting and put the ON/OFF switch back to position I.

6. Check the supply and burner pressures and adjust these, where necessary. See paragraph 3.11 Checking the supply pressure and burner pressure.

7. Check that all components of the flue gas system are properly attached.

8. Test the operation of the expansion valve of the cold supply setup. The water should spurt out.

9. Test the overflow operation of the T&P valve. The water should spurt out.

10. Check the drain pipes from the discahrge points of any valve and remove any lime buildup that may be present.

11. Drain the water heater. See paragraph 4.3 Draining the water heater.

Instruction manual DR-LA 57

9.3 Water-side maintenance

9.3.1 Introduction

9.3.2 Checking the anodes

Take care

The draught diverter and the cover may be hot.

Maintenance

The following steps should be carried out on the water side:

1. Checking the anodes.

2. Descaling and cleaning the heater.

Timely replacement of the anodes extends the service life of the water heater. The anodes that are present must be replaced as soon as they are 60% or more used up (take this into consideration when determining the maintenance frequency).

1. Remove the protective cover from the control column by unscrewing the 4 screws in the cover.

2. Detach the wiring for the flue gas thermostat from the connector block and remove the cable from the strain relief.

3. Remove the cable clamps holding the flue gas thermostat cable.

4. Disconnect the draught diverter from the flue gas discharge.

5. Undo the screws on the draught diverter.

6. Remove the draught diverter from the water heater.

7. Undo the screws of the cover on the top of the water heater.

8. Remove the cover from the water heater.

9. Remove the sealing ring from the hot water tank.

10. Loosen the anodes using suitable tools (27 mm A/F).

11. Check the anodes and if necessary, replace them.

12. Now also check the flue baffles. Replace them, if necessary. See paragraph

9.4.4 Checking the flue baffles.

13. Fit a new sealing ring around the edge of the hot water tank and replace the cover.

14. Fit the draught diverter. See paragraph 3.9.2 Fitting the draught diverter.

15. Feed the cable of the flue gas thermostat through the strain relief and attach the wiring to the connector block. See appendix 1.2 Electrical diagram DR-

LA or 1.2.2 Electrical diagram DR-LA 110 (LP gas).

16. Refit the cable clamps to the water heater and draught diverter.

17. Refit the protective cover.

9.3.3 Descaling and cleaning the heater

Scale and lime buildup prevent effective conduction of the heat to the water. Periodic cleaning and descaling prevents buildup of these deposits. This increases the service life of the appliance, and also improves the heating process.

Take the rate of scale formation into account when deciding on maintenance frequency. Scale formation depends on the local water composition, the water consumption and the water temperature setting. A water temperature setting of maximum 60

To guarantee a good, watertight seal around the cleaning opening, the gasket , O-ring g, spring washers, bolts and if necessary, the lid c should be replaced with new parts before reassembly. See Figure 9.1. A special set is obtainable from Hamworthy for this purpose.

58 Instruction manual DR-LA

c is recommended for prevention of excessive scale buildup.

Gas-side maintenance

To simplify descaling and cleaning of the tank, the appliance is equipped with two cleaning openings.

IMD-0235

Figure 9.1 Cleaning opening

1. Remove the cover plate a on the outer jacket. See Figure 9.1.

2. Carefully remove the insulation b and set it to one side. This will be needed again later.

3. Undo the bolts.

4. Remove the lid, the gasket and the O-ring.

5. Inspect the tank and remove the loose scale deposits and contamination.

6. If the scale cannot be removed by hand, then the appliance will need to be descaled using a suitable cleaner.

9.4 Gas-side maintenance

Take care

The burners may be hot.

Figure 9.2 Bolt tightening sequence

7. Close the cleaning opening. To avoid damage to the tank, the bolts that fasten the lid should be tightened with a torque no greater than 50 Nm. Use suitable tools for this. To properly seal the cleaning opening, we recommend tightening the bolts in the sequence shown in Figure 9.2.

9.4.1 Introduction

On the gas side the following steps should be carried out:

1. Cleaning the burners.

2. Cleaning the orifices.

3. Checking the flue baffles.

IMD-0282

9.4.2 Cleaning the burners

1. Detach the burners.

2. Carefully remove any contamination present on the burners.

Instruction manual DR-LA 59

9.4.3 Cleaning the orifices

9.4.4 Checking the flue baffles

Take care

The flue baffles may be hot.

Maintenance

3. Re-attach the burners.

1. Remove the orifices.

2. Remove any contamination present in the orifices.

3. Re-attach the orifices.

1. Complete steps 1 through 9 of paragraph 9.3.2 Checking the anodes.

2. Remove the flue baffles from the water heater.

3. Check the flue baffles for rust and remove any which is present.

4. Check the flue baffles for wear and replace any worn flue baffles.

5. Complete steps 13 through 17 of paragraph 9.3.2 Checking the anodes

9.5 Finalising maintenance

To finalise the maintenance carry out the following steps:

1. Fill the water heater. See paragraph 4.2 Filling the water heater.

2. Re-start the water heater. See 7.2 Starting up.

60 Instruction manual DR-LA

A Appendices

1.1 Introduction This appendix contains:

•The Electrical diagram DR-LA.

Instruction manual DR-LA 61

1.2 Electrical diagram DR-LA

1.2.1 Electrical diagram DR-LA 30 through 95 and 110 (natural gas)

1 = brown

2 = blue

3 = yel./green

4 = black

5 = white

Appendices

2 2

L L L

16151413

111

1817

12 1

230V AC 50Hz

2 14344 4 4

2419 20 21 22 23

444

2L3

NO P NC

654321 98710

FUSE

NO NCP

1211

4 44

TERMINAL STRIP CONNECTIONS:

A Earth

N Neutral L1 Phase L2 Phase input of controller L3 Phase input of combustion products discharge safety device L Phase input safety ciruit of thermostat circuit NO Normally open P PVC power supply NC Normally closed

PARTS:

A Burner control

N Neutral

A Earth

L 'Phase input of controller L "Phase output TH Phase input of thermostat circuit GV1 Phase output of gas control MAX Phase input of safety thermostat LG Phase input of hot surface igniter I Ionisatiion detection = output NO Normally open P Phase input alarm NC Normally closed F1 Fuse (T5A) R1 Relay (Max. 250V, 10A)

L"N

HN1

B Frost thermostat C Control thermostat D On/Off switch E Safety thermostat F High-limit thermostat G Gas valve H Hot surface igniter J Flame probe K Error detection L On detection M Reset button N Combustion products discharge safety device O Relay (Max. 250V, 10A)

OPTIONAL PARTS: P Main switch control Q potentiostat (for power anodes) R Week timer

L’

42121444 333 43

Figure 1.1 Electrical diagram DR-LA 30 through 95 and 110 (natural gas)

HOT

SURFACE

LLI

4 4 4

302725 26 28 29

544

62 Instruction manual DR-LA

1 = brown

2 = blue

3 = yel./green

4 = black

5 = white

1.2.2 Electrical diagram DR-LA 110 (LP gas)

230V AC 50Hz

2L3

654321 98710

FUSE

HOT SURFACE

HN1

L"N

L’

42121444 333 43

2 2

L L L

16151413

111

1817

12 1

2 14344 4 4

2419 20 21 22 23

444

NO P NC

Electrical diagram DR-LA

NO NCP

1211

4 44

4 4 4

TERMINAL STRIP CONNECTIONS:

AEarth NNeutral LPhase L1Phase input of controller

Phase input of combustion products discharge safety device

Phase input safety ciruit of thermostat circuit NO Normally open P PVC power supply NC Normally closed

PARTS:

A Burner control

N Neutral

A Earth

L' Phase input of controller

L" Phase output

TH Phase input of thermostat circuit

GV1 Phase output of gas control

MAX Phase input of safety thermostat

LG Phase input of hot surface igniter

I Ionisatiion detection = output

NO Normally open

P Phase input alarm

NC Normally closed

F1 Fuse (T5A)

R1 Relay (Max. 250V, 10A)

Figure 1.2 Electrical diagram DR-LA 110 (LP gas)

LLI

L High-limit thermostat B Frost thermostat C Control thermostat D On/Off switch E Safety thermostat F High-limit thermostat G Gas valve H Hot surface igniter J Flame probe K Error detection L On detection M Reset button N Combustion products discharge safety device O Relay (Max. 250V, 10A) P High-low control QTimer

OPTIONAL PARTS:

R Main switch control S Potentiostat (for power anodes) T Week timer

13 4 54 2 43

302725 26 28 29

444

41 4 4 2

373331 32 34 35 4038 39

H J P

3 4

16Q18

’’

4 4

L1L

1618

2424

Instruction manual DR-LA 63

Appendices

64 Instruction manual DR-LA

DORCHESTER DR-LA 30, DR-LA 40, DR-LA 60, DR-LA 75, DR-LA 95 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Table of contents

1 Introduction

1.1 About the water heater

1.2 What to do if you smell gas

1.3 Regulations and documents

1.4 Target groups The three target groups for this manual are:

Maintenance

1.6 Forms of notation The following notation is used in this manual:

1.7 Overview of this document

Introduction

2.2 Functional description of the water heater

The water heater’s heating cycle

2.4.1 Water temperature protection

2.4.2 Combustion products discharge safety device

2.4.3 flame probe

2.5.1 Unvented installation

2.5.2 Vented installation

2.5.3 Temparature and Pressure valve (T&P valve)

2.6 Indicators and Alarms

2.6.1 Volt Free Contacts

Options

2.7.1 LPG

2.7.2 Unvented Supply

2.7.3 Top to Bottom Circulation

Introduction

3 Installation

• Packaging;

• Environmental conditions;

3.3.1 Humidity and ambient temperature

3.3.2 Maximum floor loading

3.3.3 Working clearances

3.5 Installation diagram Figure 3.3 shows the water and gas connection diagrams for unvented and

3.6 Water connections, Unvented

3.6.1 Cold water side

3.6.2 Top to bottom recirculating pump

3.6.3 Hot water side

3.6.4 Drain valve

3.6.5 Circulation pipe

3.7 Water connections, Vented

3.7.1 Cold water side

3.7.2 Top to bottom recirculating pump

3.7.3 Hot water side

3.8 Gas connection

3.7.4 Circulation pipe

3.9 Flue gas discharge

3.9.1 Introduction

3.9.2 Fitting the draught diverter

3.9.3 Flue gas thermostat assembly

3.10 Electrical connection

3.10.1 Introduction

3.10.2 Preparation

3.10.3 Mains power

3.11 Checking the supply pressure and burner pressure

3.12 Conversion to a different gas category

3.12.1 Introduction

3.12.2 Conversion to a different gas category DR-LA 30 through 95

3.12.3 Conversion to a different gas category, DR-LA110

Introduction

Conversion from LP gas to natural gas

Conversion from natural gas to LP gas

4 Filling and draining

Introduction

4.2 Filling the water heater

4.2.1 Filling unvented installations

4.2.2 Filling vented installations

4.3 Draining the water heater

4.3.1 Draining unvented installations

4.3.2 Draining vented installations

5 Controls

• 5.2 Control panel;

Introduction

5.3 Explanation of the symbols

ON/OFF switch 'ON mode' / 'OFF mode'

5.5 Control thermostat Use the rotary knob of the control thermostat to set the desired water

5.6 Burner control reset button

5.7 Flue gas thermostat reset button